• Journal of Radiation Protection and Research
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• 제35권1호
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• pp.26-33
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• 2010

비파괴검사 분야의 방사선 검사(RT) 방식은 image plate (IP)를 사용한 Computed Radiography(CR) 영상시스템의 도입에 따라 필름 방식의 아날로그 영상이 점차 디지털 영상으로 교체되고 있다. 비파괴검사에서 결함을 효과적으로 검출할 수 있는 영상의 품질은 촬영 조건, 영상획득매체, 사용 선원의 종류 및 촬영 거리, 검사체 두께등이 영향을 미친다. 본 논문에서는 비파괴 검사 분야에 적용할 수 있는 감마선원의 기본 특성을 조사하였고, FUJI사에서 개발한 CR 영상 시스템에 $^{75}Se$, $^{192}Ir$ 동위원소를 적용하여 영상을 획득하였다. 획득된 영상의 gray scale을 이미지 소프트웨어를 통해 추출한 후에 대조도 및 신호대잡음비를 계산하고 비교 분석하였다. 또한 투과도계를 이용한 비교 영상을 통하여 식별도를 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4624-4642
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• 2014

Image compression is a popular research issue that focuses on the problems of reducing the size of multimedia files. Vector Quantization (VQ) is a well-known lossy compression method which can significantly reduce the size of a digital image while maintaining acceptable visual quality. A locally adaptive scheme (LAS) was proposed to improve the compression rate of VQ in 1997. However, a LAS needs extra indicators to indicate the sources, consequently the compression rate of LAS will be affected. In this paper, we propose a novel method to eliminate the LAS indicators and so improve the compression rate. The proposed method uses the concept of data hiding to conceal the indicators, thus further improving the compression rate of LAS. From experimental results, it is clearly demonstrated that the proposed method can actually eliminate the extra indicators while successfully improving the compression rate of the LAS.

• 대한방사선기술학회지:방사선기술과학
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• 제41권6호
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• pp.533-538
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• 2018

As the use of digital radiographic system has been expanded, there are some concerns an increase about in patient of radiation dose. Therefore, International Electro-technical Commission (IEC) has been proposed a standard foe exposure index (EI). In this study, the EI was measured on human chest model using computed radiography (CR). Radiation quality used RQA5 of IEC62494-1. After acquiring the chest anterior posterior image (Chest AP) by using the phantom, the EI was obtained by applying the system response. In this study, we have analyzed the images with the detector size (Full filed ROI) and the optimized image (Fit filed ROI). The EI increased proportionally with radiation dose increase. Due to the discrete increase in pixel value, the EI showed an exponential increase. The discrete increase in noise equivalent quanta (NEQ) resulted in a discrete increase in the EI. The EI of the two images used in this study increased with increasing NEQ but showed different increments. For the measurement of the EI, IEC standards must be followed. The EI should be used as an index to evaluate the image quality for quality control of X-ray image rather than as an indicator of exposure dose. When calculating the EI, the system response should be applied depending on whether or not the grid is used. The size of the field should be obtained by including only the necessary parts.

• 한국정보통신학회논문지
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• 제17권11호
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• pp.2636-2644
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• 2013

본 논문에서는 서로 다른 감지장치로부터 획득한, 특성이 상이한 다중영상인 가시광선 영상과 적외선 영상의 까다로운 영상융합을 수행할 수 있는 웨이블렛 기반 MAD순서통계량을 논의한다. 상이한 두 영상의 효과적인 영상융합을 위하여 근사부분대역의 웨이블렛 계수에 가중평균(Weighted average)법으로 융합처리하고 상세 부분대역의 웨이블렛 계수에 중앙절대편차(MAD: Median Absolute Deviation)를 이용한 임계값을 비교하여 두 영상의 장점만을 표현하는 방법을 제안한다. 특히 기존의 융합규칙들은 두 영상간의 화소나 지표 값의 대 소 관계에 의해 융합 영상이 이루어짐으로서 왜곡요소가 융합영상에 포함되어 왜곡된 융합영상을 얻을 가능성이 높다. 이러한 단점을 보완하기 위하여 제안 방법의 임계값은 잡음과 같은 왜곡요소를 배재하고 영상의 통계량을 고려하여 설정하였다. 다양한 다중영상을 기존 영상 융합 방법들과 비교하여 제안한 영상융합 방법의 우수성을 종합적 실험결과를 통하여 확인할 수 있었다. 제안된 방법은 실시간처리를 보장하기위하여 DSP와 FPGA를 이용한 하드웨어로 구현하였으며 Xilinx FPGA를 사용하였다.

• 한국측량학회지
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• 제17권2호
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• pp.129-136
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• 1999

영상분류 결과는 지형적 영향, 영상의 상태 등에 따라 전체 영상에 대하여 균일하지 않을 수 있다. 본 연구에서는 분류 결과의 불균일성과 위성영상 분류 오차의 공간적 분포를 평가하기 위해 ISDd (Index of Spatial Distribution by distance) 와 ISDs (ISD by scatteredness)의 개념을 제안하였다. ISDd는 지표화된 오분류 화소간의 거리이고, ISDs는 오분류 화소의 산포도에 관한 통계적 지표이다. 실제 위성영상에 대한 실험을 통하여 ISDd와 ISDs를 계산 및 평가하였으며, 실제 국지적 오분류 영역을 추출하여 오분류의 원인을 고찰하였다. 본 연구 결과, ISDd와 ISDs를 동시에 사용하여 오분류 화소의 국지적 밀집 여부와 밀집 정도의 평가가 가능하였으며, 그 결과를 토대로 영상의 일부분에 대한 분류결과의 채택/기각을 결정할 수 있었다. 따라서, 전체 분류정확도 외에 공간분포지표를 사용함으로써 사용자는 오분류 화소의 공간적 분포 상태를 파악할 수 있으며, 분류 결과의 적합성 및 신뢰성 판단을 위한 추가적인 기준을 가질 수 있다.

• 대한디지털의료영상학회논문지
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• 제13권2호
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• pp.63-69
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• 2011

Table strapis patient fixture for securing the patient movements and falls. if it designed to measure the abdominal circumference and used as an indicator of dose selection at CT scan. it will prevent the overexposure of dose without degradation of image quality and efficiently manage dose of each type of body to technician to deal with CT. First, in order to compare the dose used in CT image and qualitative characteristics. reference image is obtained by examining the abdominal phantom in same conditions with the hospital 120 kVp, 200 mAs, D-Dom (Dynamic Dose Of Modulation). SNR, PSNR, RMSE, MAE, CTDIvol of CT images are compared with reference image. for comparing with reference image, the image that Umbilicus level image of Abdomen CT is stored in the PACS were used. For comparison, the top 12 o'clock portion of the air drawn from the same ROI was measured. CTDIvol, mAs, etc. In order to analyze the characteristics of the image, by measuring the length of the umbilicus circumference, pattern of the dose was analyzed. by using the analyzed perimeter and dose information, To be identified visually, fixed band that scale marked were produced. Use them, If the length of circumference of less than 60 cm 100 mAs, Case of 61~80 cm 120 mAs, Case of 80~100 cm 150 mAs, more than 100 cm 200 mAs, dose selection based on the perimeter, the image was applied. by compare analyzed with the Reference Image, image quality was assessed. by compare with existing tests that equally 200 mAs applied, How much was confirmed that the dose reduction. 1. Depending on the Abdominal circumference, the average PSNR(dB) of the image that differently dose applied was 45.794. 2. Comparing with existing test. the dose of scan that adjusted the mAs depending on the circumference was decreased about 40%. SNR and PSNR of the image that obtained by adjusting the standard mAs based on dose modulation were not much different. Therefore, By choosing a low mAs. dose reduction can be obtained. and the dose selection method that measured Abdominal circumference using a fixed band can protect the overexposure and uniformly apply dose of each type of body to technician to deal with CT.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.252-263
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• 2011

In this work, for the first time, the quality of restoration in wide-field microscopy images after deconvolution was analyzed as a function of different Point Spread Functions using one deconvolution method, on a specimen of known size and on a biological specimen. The empirical Point Spread Function determination can significantly depend on the numerical aperture, refractive index of the embedding medium, refractive index of the immersion oil and cover slip thickness. The influence of all of these factors is shown in the same article and using the same microscope. We have found that the best deconvolution results are obtained when the empirical PSF utilized is obtained under the same conditions as the specimen. We also demonstrated that it is very important to quantitatively check the process' outcome using several quality indicators: Full-Width at Half-Maximum, Contrast-to-Noise Ratio, Signal-to-Noise Ratio and a Tenengrad-based function. We detected a significant improvement when using an indicator to measure the focus of the whole stack. Therefore, to qualitatively determinate the best deconvolved image between different conditions, one approach that we are pursuing is to use Tenengrad-based function indicators in images obtained using a wide-field microscope.

• 한국식생활문화학회지
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• 제27권3호
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• pp.233-239
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• 2012

The purpose of this study was to develop an evaluation indicator for the industrialization of local cuisine. We conducted a literature study, interviews with experts, and a Delphi survey. The resulting evaluation indicator was divided into four groups and nine sub-groups. The four groups were locality, taste and functionality, industrial base, and business value. The nine sub-groups were traditionality, regionality, eating quality, nutrition and functionality, condition of development, technological level, rights and policy, marketability, and ripple effects. Also 22 items were created as indicators for evaluating classes ; historicity, sustainability, rarity, awareness of local resident, the number of similar restaurant, appearance, taste, nutritional balance, health functionality, availability of raw materials, suitability of environmental exchange of market, standardization of recipe, simplification of recipe, storability, intellectual property rights, government's policy, appropriacy of price, popularization, possibility of franchise, globalization, improvement of local image, vitalization of local economy. The four most important classes corresponded to one of the four groups. These classes were sustainability, taste, state (local autonomy) policy, vitalization of local economy. The implications of this study are that the possibility of industrializing the local cuisine of each region can be evaluated and applied. Moreover, these indicators could promote the discovery of local cuisines, support planning for the commercialization of local cuisine.

• Industrial Engineering and Management Systems
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• 제7권3호
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• pp.214-227
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• 2008

Today's dynamic competitiveness requires an organization to improve its performance measurement and management. Quality Management Systems (QMS) abound, the main ones being: ISO series, Malcolm Baldridge National Quality Award (MBNQA), European Forum for Quality Management (EFQM), Six Sigma Business Scorecard and the Balanced Scorecard. Based on the literature, the IPMMM (Integrated Performance Measurement and Management Model) identified 7 key synthesized factors: leadership, strategy management and policy, customer and market, learning and growth, partnership and resources, internal processes and business results that are employed to investigate the key performance indicators of a car assembler using the Delphi methodology. In the 2 rounds of Delphi panels consisting of 20 senior management personnel, the $1^{st}$ round of 198 indicators in the IPMMM yielded 90 indicators. The $2^{nd}$ round yielded 43 performance indicators with 18 rated as critical based on the % assigned in the $1^{st}$ and $2^{nd}$ priority rating of "very important factor" and "key performance indicator" that must be ranked high on both of the priorities. The very critical indicators appeared to be: defect percentage and first time capability (tie in $1^{st}$ place) and revenue, goal setting, customer satisfaction index, on-time delivery, brand image, return on investment, Claim Occurrence Ratio, and debt being ranked from $3^{rd}$ to $10^{th}$. It can be surmised that an organization can identify and develop an appropriate set of performance indicators through the Delphi methodology and implement and manage them based on the Balanced Scorecard.

• 방송공학회논문지
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• 제26권5호
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• pp.500-507
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• 2021

가상현실 산업은 Covid-19 이후 비대면 콘텐츠 수요 급증과 메타버스에 대한 관심과 더불어 재도약할 기회를 얻었다. 따라서 이러한 흐름과 함께 가상현실 콘텐츠를 대중화를 위해서는 양질의 콘텐츠 제작과 가상현실 특성에 맞는 스토리텔링 연구가 지속적으로 이루어져야 한다. 이처럼 가상현실 특성을 적용한 콘텐츠가 사용자 피드백을 통해 효과적으로 제작되기 위해서는 해당 콘텐츠를 평가할 수 있는 정량적 지표가 필요하다. 본 연구에서는 가상현실 콘텐츠를 관람하는 과정을 분석하여 머리 움직임을 정량적 지표로 설정하였다. 이후 실험자는 5개 애니메이션을 관람하고 이에 따라 기록된 머리 움직임 정보와 몰입도 간의 상관관계를 분석하였다. 분석 결과는 머리 움직임 속도가 상대적으로 느릴 때 높은 몰입도를 나타내었고, 머리 움직임 속도가 콘텐츠 몰입도 정도를 나타내는 지표로 유의미하게 사용될 수 있다는 것을 알 수 있었다. 이렇게 도출된 결과는 이후 창작자가 가상현실 콘텐츠 제작을 할 때 프로토타입 제작 후 적용된 스토리텔링 방식의 유효성을 검증할 수 있는 정량적 지표로 사용될 수 있다. 이러한 방식은 제안된 스토리텔링 방식 문제점을 빠르게 파악하고 더 나은 방식을 제안할 수 있어 콘텐츠의 질을 향상시킨다. 본 연구는 머리 움직임 속도라는 정량적 지표를 기반으로 몰입도를 분석하는 기초연구로 양질의 가상현실 콘텐츠 제작과 가상현실 콘텐츠 대중화에 기여하고자 한다.